1. Field of the Invention
This invention relates to a centrifuge, and particularly to a linking structure for engaging a rotor to the drive shaft of a motor, etc.
2. Description of the Related Art
In a centrifuge, as diagrammed in FIG. 4, a rotor 1 that is formed as an independent component is engaged with the drive shaft 3 of a motor 2.
In such a centrifuge as this, a linking structure is employed for engaging the rotor 1 with the drive shaft 3 wherein pins 4 are implanted in the drive shaft 3, grooves 6 are formed in the inner circumferential walls of a bearing hole 6 formed in the bottom surface of the rotor 1, and the pins 4 of the drive shaft 3 are inserted into these grooves 6, thereby linking the rotor 1 to the drive shaft 3.
Thus, in the centrifuge described here, the rotor 1 is in effect supported integrally by (the drive shaft 3 of) the motor 2, wherefore, in cases where the center of gravity of the rotor 1 does not coincide with the axis center of the drive shaft 3, there is a danger of the rotor 1 being turned eccentrically. In such cases as this, the rotor 1 manifests a gyro effect whereby it seeks to maintain a horizontal orientation, whereupon there is a danger that the rotor 1 will vibrate greatly, that the drive shaft 3 will be flexed, and that the durability of the drive shaft 3 will decline. When vibration in the rotor 1 becomes great, there is a danger that the rotor 1 will be seriously damaged.
What is done, in the face of this, is to reduce the flexure on the drive shaft 3 by absorbing the load of the drive shaft 3 described above by elastically supporting the motor 2 on the equipment frame so that the motor 2 is displaced. When such a configuration as this is adopted, however, in cases where the center of gravity of the rotor 1 does not coincide with the axis center of the drive shaft 3, as noted above, the amount of eccentricity that develops when the rotor 1 is turned becomes great.
In order to resolve such problems as this, in Japanese Utility Model Laid-open No. S48-57774/1973, art is disclosed wherein, in addition to elastically supporting the motor on the equipment frame, the rotor is elastically supported by the drive shaft.
In recent years, however, centrifuges have come into widespread use wherein buckets 7 are supported by the rotor 1 so that they can freely swing, as diagrammed in FIG. 4. In centrifuges such as this, it is very difficult to make the center of gravity of the rotor 1 coincide with the drive shaft 3. Not only so, but the mass of the rotor 1 is great. Because of this, it is not possible to safely prevent eccentric turning of the rotor 1 or flexure in the drive shaft 3.